Reduction of blood pressure through a number of psychophysiologic techniques has been reported. These have included biofeedback techniques, autogenic exercises, and hypnosis. Such studies, although demonstrating that blood pressure can be altered, did not provide definitive information on how long the effects were sustained at useful levels and usually were not adequately designed. The present study is intended to determine whether a combination of psychophysiologic techniques can produce a sustained, therapeutically useful reduction in blood pressure in patients with essential hypertension.